Fix link selection documentation (#1574)

- Fix out-of-date documentation on the `Endpoint` struct.
- Add small example in DEFAULT_CONFIG.json5

DEFAULT_CONFIG.json5

@@ -19,8 +19,12 @@
 
   /// Which endpoints to connect to. E.g. tcp/localhost:7447.
   /// By configuring the endpoints, it is possible to tell zenoh which router/peer to connect to at startup.
+  ///
   /// For TCP/UDP on Linux, it is possible additionally specify the interface to be connected to:
   /// E.g. tcp/192.168.0.1:7447#iface=eth0, for connect only if the IP address is reachable via the interface eth0
+  ///
+  /// It is also possible to specify a priority range and/or a reliability setting to be used on the link.
+  /// For example `tcp/localhost?prio=6-7;rel=0` assigns priorities "data_low" and "background" to the established link.
   connect: {
     /// timeout waiting for all endpoints connected (0: no retry, -1: infinite timeout)
     /// Accepts a single value (e.g. timeout_ms: 0)
@@ -58,8 +62,12 @@
   /// Which endpoints to listen on. E.g. tcp/0.0.0.0:7447.
   /// By configuring the endpoints, it is possible to tell zenoh which are the endpoints that other routers,
   /// peers, or client can use to establish a zenoh session.
+  ///
   /// For TCP/UDP on Linux, it is possible additionally specify the interface to be listened to:
   /// E.g. tcp/0.0.0.0:7447#iface=eth0, for listen connection only on eth0
+  ///
+  /// It is also possible to specify a priority range and/or a reliability setting to be used on the link.
+  /// For example `tcp/localhost?prio=6-7;rel=0` assigns priorities "data_low" and "background" to the established link.
   listen: {
     /// timeout waiting for all listen endpoints (0: no retry, -1: infinite timeout)
     /// Accepts a single value (e.g. timeout_ms: 0)
@@ -101,7 +109,7 @@
       /// Session open waits to receive initial declares from connected peers before returning.
       /// Setting to false may cause extra traffic at startup from peers.
       declares: true,
-    }
+    },
   },
   /// Configure the scouting mechanisms and their behaviours
   scouting: {

commons/zenoh-protocol/src/core/endpoint.rs

@@ -455,18 +455,19 @@ impl fmt::Debug for ConfigMut<'_> {
 ///
 /// ## Metadata
 ///
-/// - **`priorities`**: a range bounded inclusively below and above (e.g. `2-4` signifies
-///   priorities 2, 3 and 4). This value is used to select the link used for transmission based on the
-///   Priority of the message in question.
+/// - **`prio`**: a priority range bounded inclusively below and above (e.g. `2-4` signifies
+///   priorities 2, 3 and 4). This value is used to select the link used for transmission based on
+///   the Priority of the message in question.
 ///
-///   For example, `tcp/localhost:7447?priorities=1-3` assigns priorities
+///   For example, `tcp/localhost:7447?prio=1-3` assigns priorities
 ///   [`crate::core::Priority::RealTime`], [`crate::core::Priority::InteractiveHigh`] and
 ///   [`crate::core::Priority::InteractiveLow`] to the established link.
 ///
-/// - **`reliability`**: either "best_effort" or "reliable". This value is used to select the link
-///   used for transmission based on the Reliability of the message in question.
+/// - **`rel`**: either "0" for [`crate::core::Reliability::BestEffort`] or "1" for
+///   [`crate::core::Reliability::Reliable`]. This value is used to select the link used for
+///   transmission based on the reliability of the message in question.
 ///
-///   For example, `tcp/localhost:7447?priorities=6-7;reliability=best_effort` assigns priorities
+///   For example, `tcp/localhost:7447?prio=6-7;rel=0` assigns priorities
 ///   [`crate::core::Priority::DataLow`] and [`crate::core::Priority::Background`], and
 ///   [`crate::core::Reliability::BestEffort`] to the established link.
 #[derive(Clone, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]